1. Field of the Invention
This invention relates to a solid state image pickup device comprising a solid state image sensor including a light receiving section having photoelectric conversion elements arranged in a matrix form, a charge transferring section and a transfer control section and mosaic or stripe type microfilters arranged on the light receiving section in correspondence to picture elements. Generally stating, the terms "solid state image sensor" and "solid state image pickup device" mean the same thing. However, for convenience in description, the term "solid state image sensor" as used herein is intended to mean one for monochromatic light which is used to detect only an image brightness, and the term "solid state image pickup device" as used herein is intended to mean one which is combined with microfilters for color images.
More specifically, this invention relates to a solid state image pickup device in which the order of reading photoelectric conversion elements can be changed in a predetermined range, and the periods of reading the photoelectric conversion elements are given with priority in a predetermined range.
2. Description of the Prior Art
A MOS type image pickup device comprises, as shown in the example of FIG. 1, photoelectric conversion elements 1, vertical switches 3, horizontal switches 2, a vertical shift register 5 and a horizontal shift register 4, as is well known in the art. In FIG. 1, a stripe type microfilter is provided to the photoelectric conversion elements 1 such that each element in a column is covered by the same color microfilters but the colors vary from column to column. In the MOS type image pickup device, especially a MOS type area sensor, the order of reading the photoelectric conversion elements are unequivocally determined, and the periods of reading the elements are equal to one another.
However, in the case of a solid state image pickup device for color pictures in which a mosaic type microfilter is placed on the photoelectric conversion elements, in order to balance the signal strengths of three primary colors, red, green and blue as well as the transmittances of the elements of the microfilter, it is highly desirable to change the reading period for every color. In each of the photoelectric conversion elements, the period in which no reading operation is carried out corresponds to the charge accumulating period, and therefore if the reading period can be made relatively short, then the charge stored is increased as much.
On the other hand, for a special purpose, sometimes it is required to obtain a monochromatic light picture signal for red, green or blue from a color picture solid state image pickup device.
However, these requirements cannot be satisfied by the conventional MOS type area sensor.